Armor clamping and cutting tool

ABSTRACT

A tool for clamping and cutting an armor of a cable is configured with a housing extending along a longitudinal axis and configured to receive the cable, an elongated lever having a distal end pivotally coupled to a distal end of the housing; an elongated spring having a proximal end, which is riveted to the proximal end of the housing, and a distal end which terminates at a distance from the distal ends, a clamping stud coupled to the distal end of the spring. The elongated spring and the lever are configured to have a controllably slidable contact point therebetween. A torque applied to the lever translates into a spring-bending force applied to the spring and sufficient to bring the stud in contact with the armor with a clamping force depending on the location of the point of contact and smaller than the spring-bending force.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to hand-held tools for cutting armors of cables.

2. Discussion of the Prior Art

Hand-held tools for removing armored casings are well known anddisclosed in detail in U.S. Pat. No. 4,896,909 (“'909”); U.S. Pat. No.4,359,819 (“'819”); and US Application Publication 20060021483 ('“483”)co-owned with the present application and fully incorporated herein byreference.

The patents '909 and '819 disclose hand-held tool operating so that thepivotal motion of a lever translates in the linear motion of a clampingstud which registers the cable to be cut in the desired position. Thestructure disclosed in the patents includes two pivotally coupled leversand a stud mounted on one of the levers. When the user applies a torquebringing the levers towards one another, the stud moves linearly toengage the cable to be cut with a force that can be controlled only bythe applied force. The latter may be great enough to crush the armor ofthe cable.

FIGS. 1 and 2 illustrate a structure disclosed in the publication '819and introducing a force-controlling mechanism operative to decrease aforce applied to the armor of the cable to be cut. The disclosed toolincludes traditional levers or handles 1 and 5 pivotally coupled to oneanother so that lever 1 is displaced in response to the application ofthe user applied torque. However it is not the lever that actuates astud 6, but a resilient member 7 that has one end riveted to lever 5 andthe other end to rivet 6.

In contrast to the tool disclosed in the above-mentioned patents, theforces acting on stud 6 are different. The tool is configured with lever1 having a b length, for example 5″ and has a projection 2 acting onelement 7 and spaced from pivot 4 at a distance a, such as 1.5″. Thelength of element 7 is a b′ and, for instance, equal to 5″ and thedistance between the stud and pivot 4 is 0.5″.

In contrast to the tool of the referred to patents, projection 2 doesnot act on a point of contact between stud 6 and element 7, but on aregion further removed from pivot 4. When the torque is applied,projection 2 actuates element 7, but the force acting on stud 6 isconsiderably reduced because the point of contact for all practicalpurposes becomes a pivot point which obviously the force distribution asdisclosed below.

Assuming that a 10 lbs torque Q1 is applied to lever 1, the force P1acting on element 7 at the point of contact between projection 2 andelement 7 can be determined as P1=Q1 b/a=50/1.5=33.3. Note that in theabsence of element 7 and with projection 2 urging against stud 6, thepressure applied to the stud would be 100 lbs, provided that the abovemeasurements were unchanged.

Now a force Q2 generated by element 7 on stud 6 in response the 33.3 lbsforce can be determined as Q1b′/a′, where a′ is a distance betweenriveted end 8 of element 7 and the point of contact is 4″. The Q2 isequal to 19.4 lbs. It has been observed that the users being ofdifferent physic may still need to somewhat further adjust force Q2acting on stud 6.

A need therefore exists for a force controller operative to controllablyalter the force applied a clamping stud.

BRIEF DESCRIPTION OF THE DRAWINGS

This need is satisfied by the disclosed tool disclosed in detailhereinbelow in light of the following drawings, in which:

FIGS. 1 and 2 illustrate the principle of operation of the known tool;

FIG. 3 is a side elevation of the inventive tool shown in an initialloading position, in which a small length of cable is received in acable channel, parts being broken away;

FIG. 4 is a side elevation of the inventive tool shown in a clampingposition, in which a small length of cable is clamped;

FIGS. 5A, 5B and 5C are respective top, bottom and exploded views of theforce controlling mechanism;

FIG. 6 represents a side elevation of a portion of a housing and a leversystem in accordance with another embodiment of the invention;

FIG. 7 represents a detailed view of one of the embodiments of the leversystem;

FIG. 8 represents an end portion of a retainer of the lever system shownin FIG. 7;

FIG. 9 is an elevational view of the projection provided between thespring and lever; and

FIG. 10 represents a detailed view of a formation configured to actuateone of the lever system components in response to applying an externalforce to the other component of the lever system.

SPECIFIC DESCRIPTION

Reference will now be made in detail to several embodiments of theinvention that are illustrated in the accompanying drawings. Whereverpossible, same or similar reference numerals are used in the drawingsand the description to refer to the same or like parts or steps. Thewords “connect,” “couple,” and similar terms with their inflectionalmorphemes may denote direct and immediate connections, but also includeconnections through mediate elements or devices.

FIGS. 3 and 4 illustrate a tool 10 configured with a channel 22, whichis shaped and dimensioned to selectively receive differently sizedelongated armored cables. In operation, after an armored cable 11 (FIG.4) is placed in channel 22 (FIG. 3), the user applies a force to ahand-held lever 18 and actuates a force applicator. The latter includesa leaf spring 20 extending between a housing 12 and lever 18, a clampingstud 24 displaceable substantially perpendicular to a longitudinal axisA-A into channel 22 and arresting the displacement of cable 11 and aforce controller 100 (FIG. 5A). The saw handle 32 actuates a blade 30accomplishing a longitudinal cut of armor 13.

In operation, after placing the armored cable in the channel 22, theuser holds a housing 12 and lever 18 applying to these components antorque sufficient to displace the lever from a rest position of FIG. 3to a clamping position, illustrated in FIG. 4. As the lever 18 movestowards the clamping position, a clamping stud 24 is displaced towardand urges against an armor 13 of cable 11 with a clamping forcesufficient to firmly hold armor 13 between the clamp stud 24 and thesupporting surface of the channel 22.

After reliably securing armored cable 11 in channel 22 in the clampingposition, the user applies an additional compressive force displacing ahousing member 16 relative to lever 18 and causing circular saw 30 toadvance towards and penetrate the armored casing 13. Actuation of a sawhandle 32 results in an axial cut of the armor 13.

Turning now to details of tool 10, lever 18 has a distant end 40pivotally attached to a distal end 44 (FIG. 4) of housing 12. As aresult, lever 18 is operative to pivot about a pin 28 (FIG. 3) betweenthe rest and clamping positions. In the rest position, lever 18 extendsangularly outwards relative to longitudinal axis A-A and has itsproximal end 36 spaced from the housing 12. Mounted to freely pivotabout pin 28, lever 18 pivots to the clamping position displacing thusthe proximal end 36 towards the housing 12.

The leaf spring 20, coupled to the housing 12 by its proximal end 38(FIG. 3), is configured to resist the lever handle's displacement to theclamping position. As lever 18 moves toward the clamping position of thearmor, it exerts a spring-bending force applied to spring 20. Applyingthe torque or initial compression force F1, sufficient to overcome thespringing force of spring 20, brings lever 18 and spring 20 in contactat a contact point which eventually displaces the distal end of spring20 and stud 24 towards armor 13, as illustrated in FIG. 4. Due to theconfiguration of the housing 12 and spring 20, preferably, lever 18extends substantially parallel to the longitudinal axis A-A in theclamping position. However, various configurations can be easilyimplemented so as to position lever 18 at an angle relative to thelongitudinal axis in the clamping position.

The spring 20 has a longitudinal body extending angularly outwards fromthe housing 12 and terminating in the vicinity of distal end 40 of lever18. A distal end 42 (FIG. 4) of the spring 20 is substantially alignedwith a rotation axis of circular saw 30 in a plane extendingtransversely the longitudinal axis A-A. Made from metal or engineeringplastics, spring 20 is sufficiently resilient to support lever 18 in therest position.

The stroke of clamping stud 24 is self-adjusting depending on the outerdiameter of the cable 11. Once the cable 11 is reliably locked, theclamping operation is completed, and armor 13 is ready to be cut.

Displacement of clamping stud 24 is a result of application of torque F1(FIG. 3) applying such the spring-bending force to spring 20 that thelatter bends about a contact point 62 (better seen in FIG. 9), which ispractically a pivot point for spring 20 which solely affects theclamping force applied to stud 26. As proximal end 36 of lever 18continues its displacement towards housing 12, distal end 42 of thespring 20 actuates stud 24 to move into channel 22. The clamping stud 24is preloaded on distal end 42 by a spring 80 shown in FIG. 6.

The force distribution has been disclosed in detail hereinabove. Sufficeit to say that the clamping force acting on stud 24 and, therefore,armor 13 of cable 11 is not damaging to the latter. The stroke of stud24 is also substantially smaller than in the known tools and the studitself does not need to be additionally adjusted in order to clamp cable11 regardless of the outer diameter of the latter.

Referring to FIGS. 5A-5C in addition to FIGS. 3 and 4, force controllingmechanism 100 includes a plate 102 mounted in a U-shaped trough of lever18 and a projection 63. The force acting on stud 24 can be adjusted bycontrollably changing contact point 62 at which projection 63 contactsspring 20. The further point 62 from stud 24, the smaller the forceapplied to the stud.

The configuration of mechanism 100 provides for such an adjustment byhaving plate 102 along with projection 63 controllably slide relative tolever 18 and spring 20. The realization of the adjustment includesforming spaced longitudinal slots 114 and 116, respectively, in lever 18and openings or holes 122 at respective opposite ends of plate 102. Theposition of the slots and openings/holes in lever 18 can be reversed. Inthe position of plate 102 associated with a maximally possible forceapplied to stud 24, openings 122 of plate 102 are located close torespective distal ends of the slots as shown in FIG. 5A so as to reducethe distance between the pivot point and stud 26. As the user slidesplate 102 towards the proximal ends of respective slots, the forceapplied to stud 24 (FIG. 3) decreases. The projection 63 is alsoprovided with a channel 65 aligned with opening 122 and slot 116 alltraversed by a shoulder rivet 118 which may engage the inner screw ofchannel 65 or simply press fit thereinto. The other slot 114 and holes122 are traversed by an adjustment locking screw 120.

Referring to FIG. 6, a distal end 42 of spring 20 has an openingtraversed by a head 26 of clamping stud 24. To facilitate couplingbetween clamping stud 24 and lever 20, its body may have a narrow orrecessed neck located immediately next to head 26. Thus, as the neck ofstud 24 is received within the opening of the lever 20, the head 26 isterminates under spring 20 at a distance from handle 18.

Alternatively, as shown in FIGS. 7 and 8, tool 10 includes a retainer 50configured to engage the neck of head 26 of clamping stud 24. Coupled toa distal portion of an inner side 54 (FIG. 7) of lever 20, retainer 50is made from resilient material and configured to press head 26 ofclamping stud 24 against side 54 of the lever. Note that distal end 42of spring 20 may be curved with a radius of curvature “R” slightlysmaller than a radius of curvature “r” of the retainer 50. Such aconfiguration allows the edge of retainer 50 to close a gap between thelatter and distal ends of spring 20 preventing thus inadvertentdisengagement of stud's head 26 from a recess 52 (FIG. 8). Furthermore,increasing the initial compression force, which is necessary for furthercutting of armor 13, as explained below, causes a distal edge 72 ofretainer 50 to press against and bends lever's distal end 42 outwards.

The projection 63 may have various forms and dimensions. It may beconfigured as a roller. FIG. 9, in turn, illustrates a half-moon shoestructure having its apex pressed against the lever 20.

The compression spring 80 (FIG. 6) may be braced between the undersideof the stud's head 26 and the stop 60 or directly the housing 12. Thespring 80 is so selected that its module of resilience is lower than themodule of a resilient element 46 (FIG. 3), which biases multiple housingmembers away from one another. The spring 80, similarly to spring 20, isconfigured to generate a force directed in a direction opposite to theinitial force applied to lever 18.

Referring again to FIGS. 3 and 4, housing 12 extends along longitudinalaxis A-A between a proximal end 34 (FIG. 3) and the distal end 44 (FIG.4) and includes two housing members 14 and 16. Respective proximal endsof housing members 14, 16 are pivotally connected to one anther by ahinge 32. Displacement of these housing members causes circular saw 30to advance through a slot 70 (FIG. 3), which is aligned with clampingstud 24, towards the cutting plane.

Housed in one of members 14, 16 is a resilient element 46 (FIG. 3)having resiliency module higher than spring 20. Accordingly, the initialforce F1 applied to tool 10 for displacing its components to theclamping position of FIG. 4 may be insufficient to overcome the springforce of element 46. Only upon applying the additional compressive forceF2, which exceeds the spring force of element 46 (FIG. 3), housingmembers 14, 16 are forced to pivot towards one another to the cuttingposition. The resilient element 46 includes, but of course, not limitedto, a compressive spring. Preferably, housing members 14, 16 divergefrom the proximal end 34 of housing 12 from one another. Responding tothe additional force F2, the housing members are displaced towards andextend substantially parallel to one another and to lever 18 in thecutting position of the tool.

Referring to FIGS. 3 and 10 push button 82 housed in channel 22 shiftsarmored cables with relatively small diameters on the center of thecircumference of circular saw 30.

This document describes the inventive sound transfer methods and devicesimplementing these methods for illustration purposes only. Neither thespecific embodiments of the invention as a whole, nor those of itsfeatures limit the general principles underlying the invention. Inparticular, the invention is not limited to a cable-cutting tool, butincludes various clamping devices operating in accordance with theinventive principle. The specific features described herein may be usedin some embodiments, but not in others, without departure from thespirit and scope of the invention as set forth. Many additionalmodifications are intended in the foregoing disclosure, and it will beappreciated by those of ordinary skill in the art that in some instancessome features of the invention will be employed in the absence of acorresponding use of other features. The illustrative examples thereforedo not define the metes and bounds of the invention and the legalprotection afforded the invention, which function is served by theclaims and their equivalents.

1. A tool for clamping and cutting an armor of a cable, comprising: ahousing extending along a longitudinal axis and configured to receivethe cable; an elongated lever having a distal end pivotally coupled to adistal end of the housing; an elongated spring having a proximal end,which is riveted to the proximal end of the housing, and a distal endwhich terminates at a distance from the distal ends, a clamping studcoupled to the distal end of the spring, the elongated spring and thelever being configured to have a controllably slidable contact pointtherebetween, wherein a torque applied to the lever translates into aspring-bending force applied to the spring and sufficient to bring thestud in contact with the armor.
 2. The tool of claim 1 furthercomprising a plate slidably mounted to the lever, and a formationmounted to the plate and defining the contact point with the spring, theplate and lever being axially slidable relative to one another betweenone extreme position in which a clamping force applied to the stud bythe distal end of the lever is maximal and an other extreme position inwhich the clamping force is minimal, wherein the extreme positionsdefine a range of the contact point within which the clamping forceremains smaller than the force-bending force.
 3. The tool of claim 2,wherein the elongated lever is formed with a bent portion extendingbetween the proximal and distal ends thereof and configured so that thedistal end of he elongated lever is spaced from the housing along anarcuate path of the proximal end of the lever.
 4. The tool of claim 2,wherein the clamping stud traverses the distal end of the spring and hasa head terminating between the distal ends of respective spring andlever and fixed to the elongated lever.
 5. The tool of claim 2, furthercomprising an elongated flexible retainer coupled to the elongated leverby a respective proximal end, the elongated flexible retainer having adistal end provided with a recess, the clamping stud traversing therecess and terminating between the elongated lever and flexibleretainer.
 6. The tool of claim 1, wherein the housing includes a firstand second member each having a respective proximal and free distal end,the proximal ends of the first and second members being pivotallycoupled to one another so that the first and second members diverge fromone another in the clamping position of the elongated lever handle andmove towards one another to extend substantially parallel to thelongitudinal axis in response to a second external force co-directedwith but grater than the initial external force.
 7. The tool of claim 6,wherein the respective distal end of the first member has a longitudinalslot opening into a longitudinal channel provided in the housing forreceiving the cable, the slot being aligned with the clamping stud. 8.The tool of claim 7, wherein the second member houses a circular sawextending through the elongated slot to cut an armored casing of thearmored cable upon applying the second external force to the first andsecond members of the housing.
 9. The tool of claim 8, furthercomprising a resilient member extending transversely to the longitudinalaxis between the first and second members and configured to generate aspring force biasing the first and second members apart and yielding toa second external force greater than the initial external force andsufficient to move the first and second members to a cutting position,in which the first and second members extend substantially parallel toone another.
 10. The tool of claim 1, wherein the formation includes aroller or half-moon shoe shape provided with an apex, which lies on thespring or the lever.